Engine dies when putting in gear - Maxum Boat Owners Club

twerner · 07-02-2015, 05:39 AM

Ever since I bought my '98 Maxum (1900SRL) a few months ago, it's been difficult to pull away from the dock after launching. As soon as I put it in gear it dies. In a panic, I restart the engine and throttle it out of the launch area, which I'm sure upsets my fellow boaters.

It seems to get better after about 10 minutes and idles forward without dying. That said, it's getting stressful launching the boat not knowing if it will stall in the middle of the launch area.

This is a 4-cyl Mercruiser with about 350 hours and I don't know its mechanical history.

Do you think this is an idle setting (although it gets better when warmed up), carburetor, plugs, etc.?

Thanks!
Tom

mmwjr · 07-02-2015, 01:17 PM

Are you letting the engine warm up some before casting off? This is common on carbed engines.

I let it run for a few minutes until the temp gauge starts moving up.

twerner · 07-02-2015, 03:35 PM

For about 5 min yes. Anymore and I feel like I'm holding up the boat launch. Trying to pull out to keep traffic going.

mmwjr · 07-02-2015, 04:10 PM

5 minutes should be enough.

Verify the choke is set properly and the plate moves freely. It should start opening in 1 minute and open as throttle is applied.

twerner · 07-02-2015, 06:06 PM

Thanks Mike. Before doing this, I suppose I should make sure I'm starting the engine properly. I read another post (hulltruth) about pumping the throttle once or twice before cranking the engine. I haven't been doing that to date (as a new boat owner). I'll give that a try then your suggestions?

twerner · 07-02-2015, 06:18 PM

In other words... https://youtu.be/IOOoBl1gJ4s

Calguy · 07-03-2015, 12:57 AM

If you have an Mercruiser Alpha drive it is most likely the shift interrupt switch that momentarily cuts power to engine to let gears engage. I had an old Sea Ray that also had the same problem. It needs adjustment often and is a major problem on Alpha drives. My SCR 2400 has a Bravo 2 that incorporates cone clutch so it is no longer a problem.

mmwjr · 07-03-2015, 05:44 AM

The shift interrupt only stumbles the engine when coming out of gear not going into gear.

The OP said the engine idels poor for 10 minutes until it warms up which would be a carb issue.

If the boat has sat for a week or longer I crank my engine a few seconds, then give the throttle a few pumps and crank again. I do this as the gas seems to evaporate out of the carb and the initial cranking refills it.

The guy in the video does not know what he is talking about. He said his boat has the TKS turn key start carb, this carb does not have a choke or priming circuit that requires pumping. It did not start initially because the carb was dry. Once it filled with gas it started right up. The TKS has a enrichment circuit the uses a solenoid and temp sensor in place of a choke.

jamanati · 07-04-2015, 05:37 PM

Hook up a tach to your engine and check idle speed. Tachs on the helm may be off a bit, so a good mechanics electronic tach will be more accurate. Some engines require you to check idle speed while in gear. If its too low, it may simply be stalling on you. Adjust as necessary.

twerner · 07-06-2015, 06:52 PM

Thanks guys. So would it be necessary to adjust idle speed if it eventually idles fine? As I said it's primarily getting out of the boat launch area that's the problem, even when running a few minutes.

mmwjr - are you suggesting to crank first then pump a few times then crank again? (As opposed to pumping first I guess.)

mmwjr · 07-06-2015, 11:49 PM

Yes that's what I do if the boat has sat for a week or longer.

If she idles fine after some time the idle speed should be ok as is.

What rpm does it idle at, should be around 650?

Have you checked the choke operation?

twerner · 07-06-2015, 11:56 PM

I'll take note of the RPM next time. I haven't owned a Mercruiser or I/O before so not familiar with choke operation. Let me know if there's something specific to look for or change. Thanks, Tom

mmwjr · 07-06-2015, 11:58 PM

Tom have owned a car that had a choke? No difference.

Maybe I just dated myself.

mmwjr · 07-07-2015, 12:05 AM

Go to the Documents tab on this site and find merc manual #24 on the left hand side, about half way through you will find carb info including how to set the choke.

twerner · 07-07-2015, 12:24 AM

Thanks Mike. I'll take a look. Much appreciated!

notordinary · 08-14-2015, 03:42 PM

Quote:

Originally Posted by Calguy

If you have an Mercruiser Alpha drive it is most likely the shift interrupt switch that momentarily cuts power to engine to let gears engage. I had an old Sea Ray that also had the same problem. It needs adjustment often and is a major problem on Alpha drives. My SCR 2400 has a Bravo 2 that incorporates cone clutch so it is no longer a problem.

Although your interrup switch could be out that is not your problem.
Your problem is your lower shift cable.
After time they stretch and it kills the engine because the switch cannot work correctly.
Change lower cable and you will correct your problem

mmwjr · 08-14-2015, 07:12 PM

Quote:

Originally Posted by notordinary

Although your interrup switch could be out that is not your problem.
Your problem is your lower shift cable.
After time they stretch and it kills the engine because the switch cannot work correctly.
Change lower cable and you will correct your problem

Yes the lower cable would be the issue and not the switch but the OP is having issues when shifting into gear not coming out of gear. Have never seen a bad cable cause his problem.

Kevlar7r · 08-15-2015, 10:27 PM

Quote:

Originally Posted by mmwjr

Tom have owned a car that had a choke? No difference.

Maybe I just dated myself.

I had a pos Toyota once that I had to choke with my palm to start.

Also saved some dudes on the lake one time with a flooded Merc outboard, told them to choke it out with their hands, and it fired right up.

notordinary · 08-15-2015, 10:33 PM

Quote:

Originally Posted by twerner

I'll take note of the RPM next time. I haven't owned a Mercruiser or I/O before so not familiar with choke operation. Let me know if there's something specific to look for or change. Thanks, Tom

Hey guy's it is not a choke problem if the engine is warmed up and it dies when put in gear.
If idle is set at 650 in gear.
Send me a pm and I'll send you my number. A lot easier that way.
I own a boat shop in the nw and mercruiser is what I specialize in.

mmwjr · 08-16-2015, 04:40 AM

Quote:

Originally Posted by notordinary

Hey guy's it is not a choke problem if the engine is warmed up and it dies when put in gear.
If idle is set at 650 in gear.
Send me a pm and I'll send you my number. A lot easier that way.
I own a boat shop in the nw and mercruiser is what I specialize in.

I won't argue with you expertise but I have experienced a choke not opening causing this problem wether the engine was cold or warm.

If you help solve the problem over the phone be sure to post the results here for all to learn from, thanks